C5-substituted carbapenem antibiotics, compositions containing such compounds, and methods of use in treatment of mycobacterium tuberculosis and non-tubercular mycobacteria

ABSTRACT

The present invention includes a composition, method of making and method of using a novel C5-substituted carbapenem antibiotic of formula 1: 
     
       
         
         
             
             
         
       
         
         
           
             R 1  is H or CH 3    
             R 2  is not H, and is CH 3 , or C1-C6 straight chain, or branched alkyl, or C3-C6 cycloalkyl group, or unsaturated alkenyl, including C═CH 2 ; 
             R 3  is H, CH 3 , or a C1-C6 alkyl or cycloalkyl group, a heteroatom-substituted alkyl; and 
             R 4  is a C1 to C6 alkyl, or substituted alkyl group, especially including substituents which possess positive charge, or a hydroxyl group; or 
             R 4  is an SR a , where R a  is an unsubstituted C1 to C6 alkyl group, a substituted C1 to C6 alkyl group, or a functional group that is positively charged, or which bears a positive charge when in aqueous solution at pH 7; or 
             R 4  is a CH 2 OR b , where R b =C1 to C6 alkyl or substituted alkyl groups, substituted or unsubstituted aryl, or a heteroaryl groups.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.16/006,374, filed on Jun. 12, 2018, and claims priority to U.S.Provisional Application Ser. No. 62/518,569, filed Jun. 12, 2017, theentire contents of which are incorporated herein by reference.

STATEMENT OF FEDERALLY FUNDED RESEARCH

This invention was made with government support under AI109624 awardedby the National Institutes of Health. The government has certain rightsin the invention.

TECHNICAL FIELD OF THE INVENTION

The present invention relates in general to the field of novelC5-substituted carbapenem antibiotics, compositions containing suchcompounds, and methods of use in the treatment of Mycobacteriumtuberculosis and non-tubercular Mycobacteria.

BACKGROUND OF THE INVENTION

Without limiting the scope of the invention, its background is describedin connection with the antibiotic resistance.

The 21^(st) century is witnessing the evolution and dissemination ofunprecedented levels of antimicrobial resistance and new resistancemechanisms. The evolution and dissemination of MDR, XDR, and TDR strainsof Mycobacterium tuberculosis (Mtb) and the rise of nontuberculousMycobacteria, make the development of new agents to treat theseconditions crucial. Meropenem/clavulanate has been recently proposed asa potential treatment for Mtb, with the meropenem targeting theessential transpeptidase LdtMt2, and the clavulanic acid acting as abeta-lactamase inhibitor to protect the antibiotic from hydrolyticdegradation by the beta-lactamase, BlaC. It is recognized, however, thatmeropenem is a broad spectrum antibiotic, with extensive antimicrobialactivity against numerous strains. Long term administration ofmeropenem, as would be required in treatment of tuberculosis, wouldadversely affect the microbiome, and thus structural modifications ofthe carbapenem scaffold that could improve potency and selectivity forthe mycobacterial l,d-transpeptidase would be extremely useful.

What is needed are novel compounds with improved activity, relative tomeropenem, against both Mtb and Mycobacterium abscessus (Mabs).

SUMMARY OF THE INVENTION

This application concerns modified carbapenem antibiotics that exhibitenhanced activity against mycobacterial species, especially includingMycobacterium tuberculosis and Mycobacterium abscessus. These newcarbapenems have a specific structural modification at the C5 position,which endows them with this improved activity. By contrast, currentcommercial carbapenem antibiotics all have essentially the samescaffold, with modifications occurring at the C2 position.

In one embodiment, the present invention includes a compound of formula1, or a pharmaceutically acceptable salt thereof, comprising:

R¹ is H or CH₃

R² is not H, and is CH₃, or C1-C6 straight chain, or branched alkyl, orC3-C6 cycloalkyl group, or unsaturated alkenyl, including C═CH₂;

R³ is H, CH₃, or a C1-C6 alkyl or cycloalkyl group, aheteroatom-substituted alkyl; and

R⁴ is a C1 to C6 alkyl, or substituted alkyl group, especially includingsubstituents which possess positive charge, or a hydroxyl group; or

R⁴ is an SR^(a), where R^(a) is an unsubstituted C1 to C6 alkyl group, asubstituted C1 to C6 alkyl group, or a functional group that ispositively charged, or which bears a positive charge when in aqueoussolution at pH 7; or

R⁴ is a CH₂OR^(b), where R^(b)=C1 to C6 alkyl or substituted alkylgroups, substituted or unsubstituted aryl, or a heteroaryl groups.

In one aspect, R³ is (CH₂)₂NH₂ or (CH₂)₃NH₂. In another aspect, R^(a) isa substituted pyrrolidine. In another aspect, —CO₂M, is attached to thecarbapenem nucleus at position 3, this represents a carboxylic acidgroup (M represents H), a carboxylate anion (M represents a negativecharge), a pharmaceutically acceptable ester (M represents an esterforming group) or a carboxylic acid protected by a 30 protecting group(M represents a carboxyl protecting group). In another aspect,pharmaceutically acceptable salt is —COOM, where M is a negative chargeand is balanced by a counterion. In another aspect, counterion is analkali metal cation such as sodium, potassium, calcium, magnesium, zinc,ammonium, alkylammonium cations, tetramethylammonium,tetrabutylammonium, choline, triethylhydroammonium, or meglumine,triethanolhydroammonium. In another aspect, the —CO₂M group that isattached to the carbapenem nucleus at position 3, this represents acarboxylic acid group (M represents H), a carboxylate anion (Mrepresents a negative charge), a pharmaceutically acceptable ester (Mrepresents an ester forming group) or a carboxylic acid protected by a30 protecting group (M represents a carboxyl protecting group). Inanother aspect, the pharmaceutically acceptable salt is acetate,adipate, alginate, aspartate, benzoate, benzenesulfonate, bisulfate,butyrate, citrate, camphorate, camphorsulfonate, cyclopentanepropionate,digluconate, dodecylsulfate, ethanesulfonate, fumarate, glucoheptanoate,glycerophosphate, hemisulfate, heptanoate, hexanoate, hydrochloride,hydrobromide, hydroiodide, 2-hydroxyethanesulfonate, lactate, maleate,methanesulfonate, 2-naphthalenesulfonate, nicotinate, oxalate, pamoate,pectinate, persulfate, 3-phenylpropionate, picrate, pivalate,propionate, succinate, tartrate, thiocyanate, tosylate, or undecanoate.In another aspect, the molecule comprises a biolabile ester group. Inanother aspect, biolabile ester group is selected from at least one ofpivaloyloxymethyl, acetoxymethyl, phthalidyl, indanyl, or methoxymethyl.In another aspect, M is selected from an alkoxyalkyl,alkylcarbonyloxyalkyl, alkoxycarbonyl oxyalkyl, cycloalkoxyalkyl,alkenyloxyalkyl, aryloxyalkyl, alkoxyaryl, alkylthioalkyl,cycloalkylthioalkyl, alkenylthioalkyl, arylthioalkyl or alkylthioarylgroup, or the groups can be substituted in the alkyl or aryl portionsthereof with acyl or halo groups, or acetoxymethyl, 1-acetoxyethyl,1-acetoxypropyl, pivaloyloxymethyl, 1-isopropyl oxycarbonyl oxyethyl,1-cyclohexyloxycarbonyloxyethyl, phthalidyl, or(2-oxo-5-methyl-1,3-dioxolen-4-yl)methyl. In another aspect, thecompound is further combined with a beta-lactamase inhibitor, clavulanicacid or avibactam (or related DBOs), or a boronic acid basedbeta-lactamase inhibitor. In another aspect, the compound has theformula:

In another embodiment, the present invention includes a method of makingany one of compounds 1 to 11 comprising:

The method of claim 14, wherein the molecule has the formula:

R¹ is H or CH₃

R² is not H, and is CH₃, or C1-C6 straight chain, or branched alkyl, orC3-C6 cycloalkyl group, or unsaturated alkenyl, including C═CH₂;

R³ is H, CH₃, or a C1-C6 alkyl or cycloalkyl group, aheteroatom-substituted alkyl; and

R⁴ is a C1 to C6 alkyl, or substituted alkyl group, especially includingsubstituents which possess positive charge, or a hydroxyl group; or

R⁴ is an SR^(a), where R^(a) is an unsubstituted C1 to C6 alkyl group, asubstituted C1 to C6 alkyl group, or a functional group that ispositively charged, or which bears a positive charge when in aqueoussolution at pH 7; or

R⁴ is a CH₂OR^(b), where R^(b)=C1 to C6 alkyl or substituted alkylgroups, substituted or unsubstituted aryl, or a heteroaryl groups

In another embodiment, the present invention includes an antibioticcompound of formula 1, or a pharmaceutically acceptable salt thereof,comprising:

R¹ is H or CH₃

R² is not H, and is CH₃, or C1-C6 straight chain, or branched alkyl, orC3-C6 cycloalkyl group, or unsaturated alkenyl, including C═CH₂;

R³ is H, CH₃, or a C1-C6 alkyl or cycloalkyl group, aheteroatom-substituted alkyl; and

R⁴ is a C1 to C6 alkyl, or substituted alkyl group, especially includingsubstituents which possess positive charge, or a hydroxyl group; or

R⁴ is an SR^(a), where R^(a) is an unsubstituted C1 to C6 alkyl group, asubstituted C1 to C6 alkyl group, or a functional group that ispositively charged, or which bears a positive charge when in aqueoussolution at pH 7; or

R⁴ is a CH₂OR^(b), where R^(b)=C1 to C6 alkyl or substituted alkylgroups, substituted or unsubstituted aryl, or a heteroaryl groups; and

one or more pharmaceutically acceptable excipients. In one aspect, R³ is(CH₂)₂NH₂ or (CH₂)₃NH₂. In another aspect, R^(a) is a substitutedpyrrolidine. In another aspect, —CO₂M, is attached to the carbapenemnucleus at position 3, this represents a carboxylic acid group (Mrepresents H), a carboxylate anion (M represents a negative charge), apharmaceutically acceptable ester (M represents an ester forming group)or a carboxylic acid protected by a 30 protecting group (M represents acarboxyl protecting group). In another aspect, the pharmaceuticallyacceptable salt is —COOM, where M is a negative charge and is balancedby a counterion. In another aspect, the counterion is an alkali metalcation such as sodium, potassium, calcium, magnesium, zinc, ammonium,alkylammonium cations, tetramethylammonium, tetrabutylammonium, choline,triethylhydroammonium, or meglumine, triethanolhydroammonium. In anotheraspect, the —CO₂M group that is attached to the carbapenem nucleus atposition 3, this represents a carboxylic acid group (M represents H), acarboxylate anion (M represents a negative charge), a pharmaceuticallyacceptable ester (M represents an ester forming group) or a carboxylicacid protected by a 30 protecting group (M represents a carboxylprotecting group). In another aspect, the pharmaceutically acceptablesalt is acetate, adipate, alginate, aspartate, benzoate,benzenesulfonate, bisulfate, butyrate, citrate, camphorate,camphorsulfonate, cyclopentanepropionate, digluconate, dodecylsulfate,ethanesulfonate, fumarate, glucoheptanoate, glycerophosphate,hemisulfate, heptanoate, hexanoate, hydrochloride, hydrobromide,hydroiodide, 2-hydroxyethanesulfonate, lactate, maleate,methanesulfonate, 2-naphthalenesulfonate, nicotinate, oxalate, pamoate,pectinate, persulfate, 3-phenylpropionate, picrate, pivalate,propionate, succinate, tartrate, thiocyanate, tosylate, or undecanoate.In another aspect, the molecule comprises a biolabile ester group.pivaloyloxymethyl, acetoxymethyl, phthalidyl, indanyl and methoxymethyl.In another aspect, the biolabile ester group is selected from at leastone of pivaloyloxymethyl, acetoxymethyl, phthalidyl, indanyl, ormethoxymethyl. In another aspect, M is selected from an alkoxyalkyl,alkylcarbonyloxyalkyl, alkoxycarbonyloxyalkyl, cycloalkoxyalkyl,alkenyloxyalkyl, aryloxyalkyl, alkoxyaryl, alkylthioalkyl,cycloalkylthioalkyl, alkenylthioalkyl, arylthioalkyl or alkylthioarylgroup, or the groups can be substituted in the alkyl or aryl portionsthereof with acyl or halo groups, or acetoxymethyl, 1-acetoxyethyl,1-acetoxypropyl, pivaloyloxymethyl, 1-isopropyloxycarbonyloxyethyl,1-cyclohexyloxycarbonyloxyethyl, phthalidyl, or(2-oxo-5-methyl-1,3-dioxolen-4-yl)methyl. In another aspect, theantibiotic and the one or more pharmaceutically acceptable excipientsare formulated for oral, subcutaneous, topical, pulmonary, nasal,intraalveolar, parenteral, intravenous, peritoneal, or intramuscularadministration. In another aspect, the antibiotic is further combinedwith a beta-lactamase inhibitor, clavulanic acid or avibactam (orrelated DBOs), or a boronic acid based beta-lactamase inhibitor. Inanother aspect, the compound has the formula:

In another embodiment, the present invention includes an method oftreating a bacterial infection in a subject comprising:

contacting a bacteria with an effective amount of a compound of formulaI or pharmaceutically acceptable salt thereof, comprising:

R¹ is H or CH₃

R² is not H, and is CH₃, or C1-C6 straight chain, or branched alkyl, orC3-C6 cycloalkyl group, or unsaturated alkenyl, including C═CH₂;

R³ is H, CH₃, or a C1-C6 alkyl or cycloalkyl group, aheteroatom-substituted alkyl; and

R⁴ is a C1 to C6 alkyl, or substituted alkyl group, especially includingsubstituents which possess positive charge, or a hydroxyl group; or

R⁴ is an SR^(a), where R^(a) is an unsubstituted C1 to C6 alkyl group, asubstituted C1 to C6 alkyl group, or a functional group that ispositively charged, or which bears a positive charge when in aqueoussolution at pH 7; or

R⁴ is a CH₂OR^(b), where R^(b)=C1 to C6 alkyl or substituted alkylgroups, substituted or unsubstituted aryl, or a heteroaryl groups; and

wherein the compound inhibits the growth of the bacterium in thesubject.

In one aspect, the method further comprises adding a beta-lactamaseinhibitor, clavulanic acid or avibactam (or related DBOs), or a boronicacid based beta-lactamase inhibitor. In one aspect, R³ is (CH₂)₂NH₂ or(CH₂)₃NH₂. In another aspect, R^(a) is a substituted pyrrolidine. Inanother aspect, —CO₂M, is attached to the carbapenem nucleus at position3, this represents a carboxylic acid group (M represents H), acarboxylate anion (M represents a negative charge), a pharmaceuticallyacceptable ester (M represents an ester forming group) or a carboxylicacid protected by a 30 protecting group (M represents a carboxylprotecting group). In another aspect, the pharmaceutically acceptablesalt is —COOM, where M is a negative charge and is balanced by acounterion. In another aspect, the counterion is an alkali metal cationsuch as sodium, potassium, calcium, magnesium, zinc, ammonium,alkylammonium cations, tetramethylammonium, tetrabutylammonium, choline,triethylhydroammonium, or meglumine, triethanolhydroammonium. In anotheraspect, the —CO₂M group that is attached to the carbapenem nucleus atposition 3, this represents a carboxylic acid group (M represents H), acarboxylate anion (M represents a negative charge), a pharmaceuticallyacceptable ester (M represents an ester forming group) or a carboxylicacid protected by a 30 protecting group (M represents a carboxylprotecting group). In another aspect, the pharmaceutically acceptablesalt is acetate, adipate, alginate, aspartate, benzoate,benzenesulfonate, bisulfate, butyrate, citrate, camphorate,camphorsulfonate, cyclopentanepropionate, digluconate, dodecylsulfate,ethanesulfonate, fumarate, glucoheptanoate, glycerophosphate,hemisulfate, heptanoate, hexanoate, hydrochloride, hydrobromide,hydroiodide, 2-hydroxyethanesulfonate, lactate, maleate,methanesulfonate, 2-naphthalenesulfonate, nicotinate, oxalate, pamoate,pectinate, persulfate, 3-phenylpropionate, picrate, pivalate,propionate, succinate, tartrate, thiocyanate, tosylate, or undecanoate.In another aspect, the molecule comprises a biolabile ester group.pivaloyloxymethyl, acetoxymethyl, phthalidyl, indanyl and methoxymethyl.In another aspect, the biolabile ester group is selected from at leastone of pivaloyloxymethyl, acetoxymethyl, phthalidyl, indanyl, ormethoxymethyl. In another aspect, M is selected from an alkoxyalkyl,alkylcarbonyloxyalkyl, alkoxycarbonyloxyalkyl, cycloalkoxyalkyl,alkenyloxyalkyl, aryloxyalkyl, alkoxyaryl, alkylthioalkyl,cycloalkylthioalkyl, alkenylthioalkyl, arylthioalkyl or alkylthioarylgroup, or the groups can be substituted in the alkyl or aryl portionsthereof with acyl or halo groups, or acetoxymethyl, 1-acetoxyethyl,1-acetoxypropyl, pivaloyloxymethyl, 1-isopropyloxycarbonyloxyethyl,1-cyclohexyloxycarbonyloxyethyl, phthalidyl, or(2-oxo-5-methyl-1,3-dioxolen-4-yl)methyl. In another aspect, theantibiotic and the one or more pharmaceutically acceptable excipientsare formulated for oral, subcutaneous, topical, pulmonary, nasal,intraalveolar, parenteral, intravenous, peritoneal, or intramuscularadministration. In another aspect, the antibiotic is further combinedwith a beta-lactamase inhibitor, clavulanic acid or avibactam (orrelated DBOs), or a boronic acid based beta-lactamase inhibitor. Inanother aspect, the compound has the formula:

BRIEF DESCRIPTION OF THE DRAWINGS

For a more complete understanding of the features and advantages of thepresent invention, reference is now made to the detailed description ofthe invention along with the accompanying figures and in which:

FIG. 1 is an example of C5 substituted carbapenem with enhancedanti-tubercular activity.

FIG. 2 shows a general structure of the new carbapenem antibiotics.

DETAILED DESCRIPTION OF THE INVENTION

While the making and using of various embodiments of the presentinvention are discussed in detail below, it should be appreciated thatthe present invention provides many applicable inventive concepts thatcan be embodied in a wide variety of specific contexts. The specificembodiments discussed herein are merely illustrative of specific ways tomake and use the invention and do not delimit the scope of theinvention.

To facilitate the understanding of this invention, a number of terms aredefined below. Terms defined herein have meanings as commonly understoodby a person of ordinary skill in the areas relevant to the presentinvention. Terms such as “a”, “an” and “the” are not intended to referto only a singular entity, but include the general class of which aspecific example may be used for illustration. The terminology herein isused to describe specific embodiments of the invention, but their usagedoes not limit the invention, except as outlined in the claims.

As used herein, the terms “administration of” or “administering a”compound refers to providing a compound of the invention to theindividual in need of treatment in a form that can be introduced intothat individual's body in a therapeutically useful form andtherapeutically useful amount, including, but not limited to: oraldosage forms, such as tablets, capsules, syrups, suspensions, and thelike; injectable dosage forms, such as IV, IM, or IP, and the like;transdermal dosage forms, including creams, jellies, powders, orpatches; buccal dosage forms; inhalation powders, sprays, suspensions,and the like; and rectal suppositories.

As used herein, the terms “effective amount” or “therapeuticallyeffective amount” refer to an amount of compound that when provided to athe subject elicits a biological or medical response of a tissue,system, animal or human that is being sought by the researcher,veterinarian, medical doctor or other clinician. As used herein, theterm “treatment” refers to the treatment of the mentioned conditions,particularly in a patient who demonstrates symptoms of the disease ordisorder.

As used herein, the term “excipient” refers to one or more compatiblesolid or liquid filler diluents or encapsulating substances that aresuitable for administration to a human subject. Some examples ofsubstances which can serve as excipients include sugars such as lactose,glucose and sucrose; starches such as corn-starch and potato starch;cellulose and its derivatives such as sodium carboxymethylcellulose,ethylcellulose, cellulose acetate; powdered tragacanth; malt; gelatin;talc; stearic acid; magnesium stearate; calcium sulfate; vegetable oilssuch as peanut oil, cottonseed oil, sesame oil, olive oil, corn oil andoil of theobroma; polyols such as propylene glycol, glycerine, sorbitol,mannitol, and polyethylene glycol; agar; and alginic acid; as well asother non-toxic compatible substances used in pharmaceuticalformulations. Wetting agents and lubricants such as sodium laurylsulfate, as well as coloring agents, flavoring agents, sweetening agents(including nonnutritive sweeteners such as aspartame and saccharin),tableting agents, stabilizers, antioxidants, cooling agents, andpreservatives, can also be present.

As used herein, the term “pharmaceutically acceptable” refers to acarrier, diluent, or excipient must be compatible with the otheringredients of the formulation and not be deleterious to the recipientthereof.

As used herein, the term “carrier” or “vehicle” refers to a diluent,adjuvant, excipient or vehicle with which the active compound isadministered. Such pharmaceutical vehicles can be liquids, such as waterand oils, including those of petroleum, animal, vegetable or syntheticorigin, such as peanut oil, soybean oil, mineral oil, sesame oil and thelike. The pharmaceutical vehicles can be saline, gum acacia, gelatin,starch paste, talc, keratin, colloidal silica, urea, and the like. Inaddition, auxiliary, stabilizing, thickening, lubricating and coloringagents can be used. When administered to a subject, the pharmaceuticallyacceptable vehicles are preferably sterile. Water can be the vehiclewhen the active compound is administered intravenously. Saline solutionsand aqueous dextrose and glycerol solutions can also be employed asliquid vehicles, particularly for injectable solutions. Suitablepharmaceutical vehicles also include excipients such as starch, glucose,lactose, sucrose, gelatin, malt, rice, flour, chalk, silica gel, sodiumstearate, glycerol monostearate, talc, sodium chloride, dried skim milk,glycerol, propylene glycol, water, ethanol and the like. The presentcompositions, if desired, can also contain minor amounts of wetting oremulsifying agents, or pH buffering agents.

The present invention describes compounds with improved activity,relative to meropenem, against both Mtb and Mycobacterium abscessus(Mabs).

One molecule of the present invention has the following structure 1:

Where R¹=H or CH₃;

Where R²=CH₃, or C1-C6 straight chain, or branched alkyl, or C3-C6cycloalkyl group, or unsaturated alkenyl, including C═CH₂;

Where R³ may be H, CH₃, or a C1-C6 alkyl or cycloalkyl group; and

R⁴ may be SR^(a), where R^(a)=may be an unsubstituted C1 to C6 alkylgroup, or substituted C1 to C6 alkyl group, especially includingsubstituents which themselves possess a positive charge. Oralternatively R^(a) may be a substituted or unsubstituted cyclic orheterocylic group, especially including groups which contain 1 to 3positive charges, an aryl or heteroaryl group, or substituted aryl orheteroaryl group, particularly including a substituted pyrrolidine.

Alternatively, R³ may be R3 may be heteroatom-substituted C1 to C4alkyl, particularly including (CH₂)₂NH₂, or (CH₂)₃NH₂.

Alternatively R⁴ may itself be CH₂OR^(b), where R^(b)=C1 to C6 alkyl orsubstituted alkyl groups, substituted or unsubstituted aryl orheteroaryl groups.

With respect to —CO₂M, which is attached to the carbapenem nucleus atposition 3, this represents a carboxylic acid group (M represents H), acarboxylate anion (M represents a negative charge), a pharmaceuticallyacceptable ester (M represents an ester forming group) or a carboxylicacid protected by a 30 protecting group (M represents a carboxylprotecting group).

One specific molecule is:

The pharmaceutically acceptable salts referred to above may take theform —COOM, where M is a negative charge, which is balanced by acounterion, e.g., an alkali metal cation such as sodium or potassium.Other pharmaceutically acceptable counterions may be calcium, magnesium,zinc, ammonium, or alkylammonium cations such as tetramethylammonium,tetrabutylammonium, choline, triethylhydroammonium, meglumine,triethanolhydroammonium, etc.

The pharmaceutically acceptable salts referred to above also includeacid addition salts. Thus, the Formula I compounds can be used in theform of salts derived from inorganic or organic acids. Included amongsuch salts are the following: acetate, adipate, alginate, aspartate,benzoate, benzenesulfonate, bisulfate, butyrate, citrate, camphorate,camphorsulfonate, cyclopentanepropionate, digluconate, dodecyl sulfate,ethanesulfonate, fumarate, glucoheptanoate, glycerophosphate,hemisulfate, heptanoate, hexanoate, hydrochloride, hydrobromide,hydroiodide, 2-hydroxyethanesulfonate, lactate, maleate,methanesulfonate, 2-naphthalenesulfonate, nicotinate, oxalate, pamoate,pectinate, persulfate, 3-phenylpropionate, picrate, pivalate,propionate, succinate, tartrate, thiocyanate, tosylate and undecanoate.

The pharmaceutically acceptable esters are such as would be readilyapparent to a medicinal chemist, and include, for example, thosedescribed in detail in U.S. Pat. No. 4,309,438. Included within suchpharmaceutically acceptable esters are those that are hydrolyzed underphysiological conditions, such as pivaloyloxymethyl, acetoxymethyl,phthalidyl, indanyl and methoxymethyl, and others described in detail inU.S. Pat. No. 4,479,947, relevant portions incorporated herein byreference. These are also referred to as “biolabile esters”.

Biolabile esters are biologically hydrolizable, and may be suitable fororal administration, due to good absorption through the stomach orintestinal mucosa, resistance to gastric acid degradation and otherfactors. Examples of biolabile esters include compounds in which Mrepresents an alkoxyalkyl, alkylcarbonyloxyalkyl,alkoxycarbonyloxyalkyl, cycloalkoxyalkyl, alkenyloxyalkyl, aryloxyalkyl,alkoxyaryl, alkylthioalkyl, cycloalkylthioalkyl, alkenylthioalkyl,arylthioalkyl or alkylthioaryl group. These groups can be substituted inthe alkyl or aryl portions thereof with acyl or halo groups. Thefollowing M species are examples of biolabile ester forming moieties:acetoxymethyl, 1-acetoxyethyl, 1-acetoxypropyl, pivaloyloxymethyl,1-isopropyloxycarbonyloxyethyl, 1-cyclohexyloxycarbonyloxyethyl,phthalidyl and (2-oxo-5-methyl-1,3-dioxolen-4-yl)methyl.

The synthetic methodology that was employed to make these newcarbapenems is shown in Scheme 1.

Scheme 1 involves the preparation of carbapenems of general structure 2.The detailed synthetic methodology utilized to prepare these novelcarbapenems is provided below.

(3S,4R)-4-methyl-3-[1(R)-(t-butyldimethylsilyloxy)ethyl]azetidin-2-one(3)

Dimethyl sulfide (0.2 mol) was added to a slurry of copper (I) iodide(0.2 mol) in THF at room temperature and stirred for 10 min. Theresultant solution was cooled to −50° C. and treated with methyllithium(0.4 mol, 1.6 M solution in Et₂O). The reaction was then allowed to warmto −10° C. for 20 min, and cooled back to −50° C. Then compound 2 wasadded (as a solid), and the reaction was warmed to rt over the course of1 h. After completion, the resulting mixture was treated with aq NH₄Cland the THF evaporated in vacuo. The resultant material was diluted withCH₂Cl₂ and washed with NH₄Cl, water and brine, dried over sodium sulfateand concentrated.

Yield 87%, ¹H NMR (400 MHz, CDCl₃): δ 0.09 (s, 6H), 0.90 (s, 9H), 1.23(d, J=6.24, 2H), 1.35 (d, J=6.07, 2H), 2.83 (m, 1H), 3.85 (m, 1H), 4.21(m, 1H), 5.78 (s, 1H).

(3S,4R)-4-acetoxy-4-methyl-3-[1(R)-(t-butyldimethylsilyloxy)ethyl]azetidin-2-one(4)

To a solution of compound 3 (12.0 mmol) in EtOAc (80 mL), acetic acid (6mL) was added followed by RuCl₃.3H₂O (0.62 mmol) and NaOAc (3 mmol) atrt. Then freshly distilled CH₃CHO (1.5 mL) was added quickly and theatmosphere was replaced with an oxygen balloon.

The reaction mixture was stirred for 15 min and CH₃CHO (1.5 mL) wasadded again. The reaction was allowed to stir for another 15 min. Afterthe reaction was completed, diluted with EtOAc (100 mL) and the organiclayer was washed by NaHCO₃, water and dried over sodium sulfate thenpurified through column.

Yield 75%, ¹H NMR (400 MHz, CDCl₃): δ 0.15 (m, 6H), 0.95 (s, 9H), 1.45(d, J=6.13, 3H), 1.98 (s, 3H), 2.12 (s, 3H), 3.18 (d, J=7.12, 1H), 4.33(m, 1H), 6.95 (s, 1H).

(3R,4S)-4-(p-Nitrobenzyl-2-diazoacetoacetate)-4-methyl-3-[1(R)-(t-butyldimethylsilyloxy)ethyl]azetidin-2-one(6)

To a solution of compound 4 (9.3 mol) in anhydrous CH₂Cl₂ (100 mL),compound 5 (18.6 mol) and ZnCl₂ (4.7 mL, 1 M solution in Et₂O) wasadded. The resulting mixture was stirred for 30 min at 40° C. After thereaction was completed, diluted with CH₂Cl₂ (100 mL), washed withNaHCO₃, water and brine, dried over sodium sulfate, evaporated thesolvent in vacuo and purified through column.

Yield 51%, ¹H NMR (400 MHz, CDCl₃): δ 0.18 (s, 6H), 0.98 (s, 9H), 2.23(d, J=6.07, 3H), 2.56 (s, 3H), 3.55 (m, 1H), 4.31 (m, 1H), 5.44 (s, 2H),7.61 (d, J=7.95, 2H), 8.35 (d, J=8.05, 2H).

(3R,4S)-4-(p-Nitrobenzyl-2-diazoacetoacetate)-4-methyl-3-(1-hydroxyethyl)azetidin-2-one(7)

To a solution of compound 6 (1.8 g) in MeOH (8 mL), HCl (8 mL, solutionin water 5 M) was added and the reaction at rt and stirred for 1 h.After the reaction was completed, the solvent was evaporated in vacuoand the product was used for the next step.

Yield 95%, ¹H NMR (400 MHz, CDCl₃): δ 1.39 (d, J=6.12, 3H), 1.56 (s,3H), 2.91 (d, J=10.32, 1H), 3.32 (d, J=2.56, 2H), 4.16 (s, J=5.72, 1H),5.33 (s, 2H), 7.56 (d, J=7.96, 2H), 8.24 (d, J=8.04, 2H).

(2R,5R,6S)-5-methyl-4-Nitrobenzylester-6-((R)-1-hydroxyethyl)-3,7-dioxo-1-azabicyclo[3.2.0]heptane-2-carboxylicacid (8)

To a solution of compound 7 (3.8 mmol) in EtOAc 15 mL, Rh₂(OAc)₄ (0.19mmol) was added. The reaction mixture was heated to reflux for 30 min.After the reaction was completed, the solvent was evaporated in vacuothe product was used directly for the next step.

Yield 99%, ¹H NMR (400 MHz, CDCl₃): δ 1.48 (q, J=6.20, 2H), 1.60 (d,J=6.04, 2H), 2.59 (q, J=16.2, 2H), 3.22 (d, J=9.88, 1H), 4.39 (m, 1H),5.27 (m, 2.02), 7.56 (d, J=8.76, 2H), 8.25 (d, J=8.12, 2H).

(5R,6S)-5-methyl-3-[[(3S,5S)₅-[(dimethylamino)carbonyl]-1-[[(4-nitrophenyl)methoxy]carbonyl]-3-pyrrolidinyl]thio]-4-Nitrobenzyl-6-((R)-1-hydroxyethyl)-7-oxo-1-azabicyclo[3.2.0]hept-2-ene-2-carboxylate(10)

To a solution of compound 8 (2 mmol) in dry acetonitrile (8 mL),diphenylphosphoryl chloride (2 mmol) and (iPr)₂NEt (2 mmol) was added−40° C. The reaction mixture was stirred for 20 min and allowed to warmto −10° C. Then compound 9 (2 mmol) was added to the previous mixturefollowed by diisopropylethylamine (2 mmol) at −40° C. The reaction wasstirred for 30 min at −40° C. Then the resulting mixture was dilutedwith EtOAc (30 mL), and the organic layer was washed with NaHCO₃, NH₄Cland brine, concentrated in vacuo and purified by column.

Yield 35%, ¹H NMR (400 MHz, CDCl₃): δ 1.44 (d, J=5.72, 2H), 1.61 (d,J=3.96, 2H), 3.00 (2d, 6H), 3.15 (d, J=3.84, 1H), 3.56 (m, 2H), 4.28 (m,1H), 5.12 (d, J=8.68, 1H), 5.22 (m, 4H), 5.30 (d, J=8.34, 1H), 5.52 (d,J=13.8, 1H), 7.45 (m, 4H), 8.23 (m, 4H).

(5R,6S)-5-methyl-3-[[(3S,5S)5-[(dimethylamino)carbonyl-3-pyrrolidinyl]thio]-6-((R)-1-hydroxyethyl)-7-oxo-1-azabicyclo[3.2.0]hept-2-ene-2-carboxylateAcid 11

A slurry of compound 10 (300 mg, 0.422 mmol) with Pd/C (300 mg) in EtOAc(20 mL) and buffer (pH=6, 20 mL) was shaken on a Parr hydrogenator at 50psi H₂ pressure for 90 min. The solution was then filtered throughcelite to remove the catalyst. The aqueous layer was separated andwashed with ether, then concentrated and purified through column.

Yield 19%, ¹H NMR (400 MHz, D₂O): δ 1.17 (d, J=5.43, 3H), 1.83 (m, 1H),1.92 (m, 1H), 2.75 (m, 2H), 2.93 (m, 6H), 3.28 (m, 2H), 3.65 (m, 2H),3.85 (m, 1H), 4.12 (m, 1H).

Data on Compound 11

TABLE 1 MIC values (M) of selected carbapenems against Mtb and MabCompound Mtb Mabs Meropenem 0.83 3.25 11 0.47 0.73

The following additional terms are as defined herein. The term “alkyl”,“alkenyl”, “alkynyl” and “alkylene” denotes hydrocarbon chains typicallyranging from about 1 to about 12 carbon atoms in length, preferably 1 toabout 6 atoms, and includes straight and branched chains. Unlessotherwise noted, in one embodiment of any alkyl or alkylene referred toherein is C1-C6 alkyl (e.g., methyl or ethyl).

The term “cycloalkyl” denotes a saturated or unsaturated cyclichydrocarbon chain, including bridged, fused, or spiro cyclic compounds,preferably comprising 3 to about 12 carbon atoms, more preferably 3 toabout 8.

The term “aryl” denotes one or more aromatic rings, each of 5 or 6 corecarbon atoms. Multiple aryl rings may be fused, as in naphthyl orunfused, as in biphenyl. Aryl rings may also be fused or unfused withone or more cyclic hydrocarbon, heteroaryl, or heterocyclic rings.

The term “heteroaryl” denotes an aryl group containing from one to fourheteroatoms, preferably N, O, or S, or a combination thereof, whichheteroaryl group is optionally substituted at carbon or nitrogen atom(s)with C1-C6 alkyl, —CF₃, phenyl, benzyl, or thienyl, or a carbon atom inthe heteroaryl group together with an oxygen atom form a carbonyl group,or which heteroaryl group is optionally fused with a phenyl ring.Heteroaryl rings may also be fused with one or more cyclic hydrocarbon,heterocyclic, aryl, or heteroaryl rings. Heteroaryl includes, but is notlimited to, 5-membered heteroaryls having one hetero atom (e.g.,thiophenes, pyrroles, furans); 5-membered heteroaryls having twoheteroatoms in 1,2 or 1,3 positions (e.g., oxazoles, pyrazoles,imidazoles, thiazoles, purines); 5-membered heteroaryls having threeheteroatoms (e.g., triazoles, thiadiazoles); 5-membered heteroarylshaving 3 heteroatoms; 6-membered heteroaryls with one heteroatom (e.g.,pyridine, quinoline, isoquinoline, phenanthrine,5,6-cycloheptenopyridine); 6-membered heteroaryls with two heteroatoms(e.g., pyridazines, cinnolines, phthalazines, pyrazines, pyrimidines,quinazolines); 6-membered heteroaryls with three heteroatoms (e.g.,1,3,5-triazine); and 6-membered heteroaryls with four heteroatoms.

The term “heterocycle” or “heterocyclic” denotes one or more rings of5-12 atoms, preferably 5-7 atoms, with or without unsaturation oraromatic character and at least one ring atom which is not carbon.Preferred heteroatoms include sulfur, oxygen, and nitrogen. Multiplerings may be fused.

The term “heteroatom” denotes any non-carbon atom in a hydrocarbonanalog compound. Examples include oxygen, sulfur, nitrogen, phosphorus,arsenic, silicon, selenium, tellurium, tin, and boron.

The term “alkylene” denotes a divalent alkyl group as defined above,such as methylene (—CH2-), propylene (—CH2 CH2 CH2-), chloroethylene(—CHClCH2-), 2-thiobutene —CH2 CH(SH)CH2 CH2,1-bromo-3-hydroxyl-4-methylpentene (—CHBrCH2 CH(OH)CH(CH3)CH2-), and thelike.

The term “alkenyl” denotes branched or unbranched hydrocarbon chainscontaining one or more carbon-carbon double bonds.

The term “alkynyl” denotes branched or unbranched hydrocarbon chainscontaining one or more carbon-carbon triple bonds.

The term “aryl” denotes a chain of carbon atoms which form at least onearomatic ring having preferably between about 6-14 carbon atoms, such asphenyl, naphthyl, and the like, and which may be substituted with one ormore functional groups which are attached commonly to such chains, suchas hydroxyl, bromo, fluoro, chloro, iodo, mercapto or thio, cyano,cyanoamido, alkylthio, heterocycle, aryl, heteroaryl, carboxyl,carbalkoyl, alkyl, alkenyl, nitro, amino, alkoxyl, amido, and the liketo form aryl groups such as biphenyl, iodobiphenyl, methoxybiphenyl,anthryl, bromophenyl, iodophenyl, chlorophenyl, hydroxyphenyl,methoxyphenyl, formylphenyl, acetylphenyl, trifluoromethylthiophenyl,trifluoromethoxyphenyl, alkylthiophenyl, trialkylammoniumphenyl,amidophenyl, thiazolylphenyl, oxazolylphenyl, imidazolylphenyl,imidazolylmethylphenyl, and the like.

The term “alkoxy” denotes —OR—, wherein R is alkyl.

The term “amido” denotes an amide linkage: —C(O)NHR (wherein R ishydrogen or alkyl).

The term “amino” denotes an amine linkage: —NR—, wherein R is hydrogenor alkyl. The term “carboxyl” denotes —C(O)O—, and the term “carbonyl”denotes —C(O)—.

The term “alkylcarboxyl” denote an alkyl group as defined abovesubstituted with a C(O)O group, for example, CH3 C(O)O—, CH3 CH2 C(O)O—,etc.

The term “carbocycle” denotes cyclic hydrocarbon chain having about 5 toabout 8 ring carbons such as cyclopentyl, cylcohexyl, etc. These groupscan be optionally substituted with one or more functional groups asdefined under “alkyl” above.

The term “halogen” includes chlorine, fluorine, bromine, iodine andmixtures thereof

The term “heterocycle” denotes straight chain or ring system that maycontain from zero to four heteroatoms selected from N, O, and S, whereinthe nitrogen and sulfur atoms are optionally oxidized, and the nitrogenatom(s) are optionally quaternized.

The term “carbamoyl” denotes the group —C(O)NH2.

The term “hydroxyalkyl” denotes an alkyl group as defined above which issubstituted by a hydroxy group.

The term “alkylcarbonyl”, alone or in combination, means an acyl groupderived from an alkanecarboxylic acid, i.e. alkyl-C(O)—, such as acetyl,propionyl, butyryl, valeryl, 4-methylvaleryl etc.

It is contemplated that any embodiment discussed in this specificationcan be implemented with respect to any method, kit, reagent, orcomposition of the invention, and vice versa. Furthermore, compositionsof the invention can be used to achieve methods of the invention.

It will be understood that particular embodiments described herein areshown by way of illustration and not as limitations of the invention.The principal features of this invention can be employed in variousembodiments without departing from the scope of the invention. Thoseskilled in the art will recognize, or be able to ascertain using no morethan routine experimentation, numerous equivalents to the specificprocedures described herein. Such equivalents are considered to bewithin the scope of this invention and are covered by the claims.

All publications and patent applications mentioned in the specificationare indicative of the level of skill of those skilled in the art towhich this invention pertains. All publications and patent applicationsare herein incorporated by reference to the same extent as if eachindividual publication or patent application was specifically andindividually indicated to be incorporated by reference.

The use of the word “a” or “an” when used in conjunction with the term“comprising” in the claims and/or the specification may mean “one,” butit is also consistent with the meaning of “one or more,” “at least one,”and “one or more than one.” The use of the term “or” in the claims isused to mean “and/or” unless explicitly indicated to refer toalternatives only or the alternatives are mutually exclusive, althoughthe disclosure supports a definition that refers to only alternativesand “and/or.” Throughout this application, the term “about” is used toindicate that a value includes the inherent variation of error for thedevice, the method being employed to determine the value, or thevariation that exists among the study subjects.

As used in this specification and claim(s), the words “comprising” (andany form of comprising, such as “comprise” and “comprises”), “having”(and any form of having, such as “have” and “has”), “including” (and anyform of including, such as “includes” and “include”) or “containing”(and any form of containing, such as “contains” and “contain”) areinclusive or open-ended and do not exclude additional, unrecitedelements or method steps. In embodiments of any of the compositions andmethods provided herein, “comprising” may be replaced with “consistingessentially of” or “consisting of”. As used herein, the phrase“consisting essentially of” requires the specified integer(s) or stepsas well as those that do not materially affect the character or functionof the claimed invention. As used herein, the term “consisting” is usedto indicate the presence of the recited integer (e.g., a feature, anelement, a characteristic, a property, a method/process step or alimitation) or group of integers (e.g., feature(s), element(s),characteristic(s), property(ies), method/process steps or limitation(s))only.

The term “or combinations thereof” as used herein refers to allpermutations and combinations of the listed items preceding the term.For example, “A, B, C, or combinations thereof” is intended to includeat least one of: A, B, C, AB, AC, BC, or ABC, and if order is importantin a particular context, also BA, CA, CB, CBA, BCA, ACB, BAC, or CAB.Continuing with this example, expressly included are combinations thatcontain repeats of one or more item or term, such as BB, AAA, AB, BBC,AAABCCCC, CBBAAA, CABABB, and so forth. The skilled artisan willunderstand that typically there is no limit on the number of items orterms in any combination, unless otherwise apparent from the context.

As used herein, words of approximation such as, without limitation,“about”, “substantial” or “substantially” refers to a condition thatwhen so modified is understood to not necessarily be absolute or perfectbut would be considered close enough to those of ordinary skill in theart to warrant designating the condition as being present. The extent towhich the description may vary will depend on how great a change can beinstituted and still have one of ordinary skill in the art recognize themodified feature as still having the required characteristics andcapabilities of the unmodified feature. In general, but subject to thepreceding discussion, a numerical value herein that is modified by aword of approximation such as “about” may vary from the stated value byat least ±1, 2, 3, 4, 5, 6, 7, 10, 12 or 15%.

All of the compositions and/or methods disclosed and claimed herein canbe made and executed without undue experimentation in light of thepresent disclosure. While the compositions and methods of this inventionhave been described in terms of preferred embodiments, it will beapparent to those of skill in the art that variations may be applied tothe compositions and/or methods and in the steps or in the sequence ofsteps of the method described herein without departing from the concept,spirit and scope of the invention. All such similar substitutes andmodifications apparent to those skilled in the art are deemed to bewithin the spirit, scope and concept of the invention as defined by theappended claims.

To aid the Patent Office, and any readers of any patent issued on thisapplication in interpreting the claims appended hereto, applicants wishto note that they do not intend any of the appended claims to invokeparagraph 6 of 35 U.S.C. § 112, U.S.C. § 112 paragraph (f), orequivalent, as it exists on the date of filing hereof unless the words“means for” or “step for” are explicitly used in the particular claim.

For each of the claims, each dependent claim can depend both from theindependent claim and from each of the prior dependent claims for eachand every claim so long as the prior claim provides a proper antecedentbasis for a claim term or element.

What is claimed is:
 1. A compound of formula 1, or a pharmaceuticallyacceptable salt thereof, comprising:

R¹ is H or CH₃ R² is not H, and is CH₃, or C1-C6 straight chain, orbranched alkyl, or C3-C6 cycloalkyl group, or unsaturated alkenyl,including C═CH₂; R³ is H, CH₃, or a C1-C6 alkyl or cycloalkyl group, aheteroatom-substituted alkyl; and R⁴ is a C1 to C6 alkyl, substitutedalkyl group, or a substituent with a positive charge, or a hydroxylgroup; or R⁴ is an SR^(a), where R^(a) is an unsubstituted C1 to C6alkyl group, a substituted C1 to C6 alkyl group; or R⁴ is a CH₂OR^(b),where R^(b)=C1 to C6 alkyl or substituted alkyl groups, substituted orunsubstituted aryl, or a heteroaryl groups; and wherein M is acarboxylic acid group, M is a negative charge in a carboxylate anion, Mis an ester-forming group of a pharmaceutically acceptable ester, or Mis a carboxyl protecting group of a carboxylic acid.
 2. The compound ofclaim 1, wherein R³ is (CH₂)₂NH₂ or (CH₂)₃NH₂.
 3. The compound of claim1, wherein —CO₂M is attached to the carbapenem nucleus at position 3 ora carboxylic acid group.
 4. The compound of claim 1, wherein M has anegative charge and is balanced by a counterion, wherein the counterionis an alkali metal cation selected from sodium, potassium, calcium,magnesium, zinc, ammonium, alkylammonium cations, tetramethylammonium,tetrabutylammonium, choline, triethylhydroammonium, or meglumine,triethanolhydroammonium.
 5. The compound of claim 1, wherein thepharmaceutically acceptable salt is acetate, adipate, alginate,aspartate, benzoate, benzenesulfonate, bisulfate, butyrate, citrate,camphorate, camphorsulfonate, cyclopentanepropionate, digluconate,dodecylsulfate, ethanesulfonate, fumarate, glucoheptanoate,glycerophosphate, hemisulfate, heptanoate, hexanoate, hydrochloride,hydrobromide, hydroiodide, 2-hydroxyethanesulfonate, lactate, maleate,methanesulfonate, 2-naphthalenesulfonate, nicotinate, oxalate, pamoate,pectinate, persulfate, 3-phenylpropionate, picrate, pivalate,propionate, succinate, tartrate, thiocyanate, tosylate, or undecanoate.6. The compound of claim 1, wherein the molecule comprises a biolabileester group.
 7. The compound of claim 6, wherein the biolabile estergroup is selected from at least one of pivaloyloxymethyl, acetoxymethyl,phthalidyl, indanyl, or methoxymethyl.
 8. The compound of claim 1,wherein M is selected from an alkoxyalkyl, alkylcarbonyloxyalkyl,alkoxycarbonyloxyalkyl, cycloalkoxyalkyl, alkenyloxyalkyl, aryloxyalkyl,alkoxyaryl, alkylthioalkyl, cycloalkylthioalkyl, alkenylthioalkyl,arylthioalkyl or alkylthioaryl group, or the groups can be substitutedin the alkyl or aryl portions thereof with acyl or halo groups, oracetoxymethyl, 1-acetoxyethyl, 1-acetoxypropyl, pivaloyloxymethyl,1-isopropyloxycarbonyloxyethyl, 1-cyclohexyloxycarbonyloxyethyl,phthalidyl, or (2-oxo-5-methyl-1,3-dioxolen-4-yl)methyl.
 9. The compoundof claim 1, wherein the compound is further combined with abeta-lactamase inhibitor, clavulanic acid or avibactam, or a boronicacid based beta-lactamase inhibitor.
 10. A method of making any one ofcompounds 1 to 11 comprising:

and wherein the molecule has the formula 1

R¹ is H or CH₃ R² is not H, and is CH₃, or C1-C6 straight chain, orbranched alkyl, or C3-C6 cycloalkyl group, or unsaturated alkenyl,including C═CH₂; R³ is H, CH₃, or a C1-C6 alkyl or cycloalkyl group, aheteroatom-substituted alkyl; and R⁴ is a C1 to C6 alkyl, or substitutedalkyl group, especially including substituents which possess positivecharge, or a hydroxyl group; or R⁴ is an SR^(a), where R^(a) is anunsubstituted C1 to C6 alkyl group, a substituted C1 to C6 alkyl group;or R⁴ is a CH₂OR^(b), where R^(b)=C1 to C6 alkyl or substituted alkylgroups, substituted or unsubstituted aryl, or a heteroaryl groups; andwherein M is a carboxylic acid group, M is a negative charge in acarboxylate anion, M is an ester-forming group of a pharmaceuticallyacceptable ester, or M is a carboxyl protecting group of a carboxylicacid.
 11. An antibiotic compound of formula 1, or a pharmaceuticallyacceptable salt thereof, comprising:

R¹ is H or CH₃ R² is not H, and is CH₃, or C1-C6 straight chain, orbranched alkyl, or C3-C6 cycloalkyl group, or unsaturated alkenyl,including C═CH₂; R³ is H, CH₃, or a C1-C6 alkyl or cycloalkyl group, aheteroatom-substituted alkyl; and R⁴ is a C1 to C6 alkyl, or substitutedalkyl group, especially including substituents which possess positivecharge, or a hydroxyl group; or R⁴ is an SR^(a), where R^(a) is anunsubstituted C1 to C6 alkyl group, a substituted C1 to C6 alkyl group,or a functional group that is positively charged, or has a positivecharge in aqueous solution at pH 7; or R⁴ is a CH₂OR^(b), where R^(b)=C1to C6 alkyl or substituted alkyl groups, substituted or unsubstitutedaryl, or a heteroaryl groups, wherein M is a carboxylic acid group, M isa negative charge of a carboxylate anion, M is an ester forming group ofa pharmaceutically acceptable ester, or M is a carboxyl protecting groupof a carboxylic acid; and one or more pharmaceutically acceptableexcipients.
 12. The antibiotic of claim 11, wherein R³ is (CH₂)₂NH₂ or(CH₂)₃NH₂.
 13. The antibiotic of claim 11, wherein a —CO₂M is attachedto the carbapenem nucleus at position
 3. 14. The antibiotic of claim 11,wherein the pharmaceutically acceptable salt is —COOM, where M is anegative charge and is balanced by a counterion.
 15. The antibiotic ofclaim 14, wherein the counterion is an alkali metal cation selected fromsodium, potassium, calcium, magnesium, zinc, ammonium, alkylammoniumcations, tetramethylammonium, tetrabutylammonium, choline,triethylhydroammonium, or meglumine, triethanolhydroammonium.
 16. Theantibiotic of claim 11, wherein the pharmaceutically acceptable salt isacetate, adipate, alginate, aspartate, benzoate, benzenesulfonate,bisulfate, butyrate, citrate, camphorate, camphorsulfonate,cyclopentanepropionate, digluconate, dodecylsulfate, ethanesulfonate,fumarate, glucoheptanoate, glycerophosphate, hemisulfate, heptanoate,hexanoate, hydrochloride, hydrobromide, hydroiodide,2-hydroxyethanesulfonate, lactate, maleate, methanesulfonate,2-naphthalenesulfonate, nicotinate, oxalate, pamoate, pectinate,persulfate, 3-phenylpropionate, picrate, pivalate, propionate,succinate, tartrate, thiocyanate, tosylate, or undecanoate.
 17. Theantibiotic of claim 11, wherein the compound comprises a biolabile estergroup, pivaloyloxymethyl, acetoxymethyl, phthalidyl, indanyl ormethoxymethyl.
 18. The antibiotic of claim 11, wherein M is selectedfrom an alkoxyalkyl, alkylcarbonyloxyalkyl, alkoxycarbonyloxyalkyl,cycloalkoxyalkyl, alkenyloxyalkyl, aryloxyalkyl, alkoxyaryl,alkylthioalkyl, cycloalkylthioalkyl, alkenylthioalkyl, arylthioalkyl oralkylthioaryl group, or the groups can be substituted in the alkyl oraryl portions thereof with acyl or halo groups, or acetoxymethyl,1-acetoxyethyl, 1-acetoxypropyl, pivaloyloxymethyl,1-isopropyloxycarbonyloxyethyl, 1-cyclohexyloxycarbonyloxyethyl,phthalidyl, or (2-oxo-5-methyl-1,3-dioxolen-4-yl)methyl.
 19. Theantibiotic of claim 11, wherein the antibiotic and the one or morepharmaceutically acceptable excipients are formulated for oral,subcutaneous, topical, pulmonary, nasal, intraalveolar, parenteral,intravenous, peritoneal, or intramuscular administration.
 20. Theantibiotic of claim 11, is further combined with a beta-lactamaseinhibitor, clavulanic acid or avibactam, or a boronic acid basedbeta-lactamase inhibitor.
 21. The antibiotic of claim 11, wherein thecompound has the formula:


22. A method of treating a Mycobacterium sp. infection in a subjectcomprising: contacting the Mycobacterium sp. with an effective amount ofa compound of formula I or pharmaceutically acceptable salt thereof,comprising:

R¹ is H or CH₃ R² is not H, and is CH₃, or C1-C6 straight chain, orbranched alkyl, or C3-C6 cycloalkyl group, or unsaturated alkenyl,including C═CH₂; R³ is H, CH₃, or a C1-C6 alkyl or cycloalkyl group, aheteroatom-substituted alkyl; and R⁴ is a C1 to C6 alkyl, or substitutedalkyl group, especially including substituents which possess positivecharge, or a hydroxyl group; or R⁴ is an SR^(a), where R^(a) is anunsubstituted C1 to C6 alkyl group, a substituted C1 to C6 alkyl group,or a functional group that is positively charged, or which bears apositive charge when in aqueous solution at pH 7; or R⁴ is a CH₂OR^(b),where R^(b)=C1 to C6 alkyl or substituted alkyl groups, substituted orunsubstituted aryl, or a heteroaryl groups, wherein M is a carboxylicacid group, M is a negative charge of a carboxylate anion, M is an esterforming group of a pharmaceutically acceptable ester, or M is a carboxylprotecting group of a carboxylic acid; and wherein the compound inhibitsthe growth of the bacterium in the subject.